Highly sensitive photodetectors comprised of Group III-V alloys are finding increasing application in the optoelectronics industry. In such a device, incident radiation in the form of photons is absorbed in a light absorptive region resulting in the generation of electron-hole pairs and a detectable current flow. The quantum efficiency, "QE", of such a device is the ratio of the number of electrons in the detectable current flow to the number of photons incident on the device. It will be appreciated that the higher the QE, the more efficient the device. A means of significantly increasing the QE of such sensitive photodetectors is provided in accordance with this invention.